Strong communication skills are a requirement that is listed on just about every job description.  One way to demonstrate such skills is to be proficient in writing professional-looking e-mails to employers.  The article below is specifically referring to e-mailing a professor, but all of the tips apply to e-mailing an employer as well.

  1. Be formal
  2. Be specific
  3. Be thorough
  4. Be kind
  5. PROOFREAD

Check out the article for more details:
http://www.usatodayeducate.com/staging/index.php/campuslife/five-things-to-remember-when-e-mailing-a-professor